remove microphone noise caused by clothing rustle on microphone

Normal Noise Reduction won't help with intermittent noise unfortunately. The only way is to try and identify the rustles in the Spectral view and try to paint them out but it won't be easy as it depends on whether it is over speech or just, if you are lucky, in the gaps.

I have used Copy/Mix Paste quite successfully in spectral view, using an adjacent area of ambient which does not include the rustle.  I find this a lot quicker than the paint brush.  Using spectral view you can select a rectangle of the required time duration and frequency range for copying - the rustle is most obvious at higher frequencies.  So you can eliminate these whilst leaving the speech unaffected.

These days, I seem to do all my editing in spectral view. 

Glad it helped!  You will never remove all the rustle unless it is in an area where there is no wanted sound, but the technique I describe reduces its impact.  Ryclark's method is needed where the rustle is among wanted sound - my work is wildlife, and I have this problem a lot with birdsong, which is generally higher frequency than speech.

The key is not to be too heavy handed, or your result can all too easily sound very artificial, and in many ways worse that the impaired original.